Objective To prospectively validate the CT-Valve score, a new risk score designed to identify patients with valvular heart disease at a low risk of coronary artery disease (CAD) who could benefit from multislice CT (MSCT) first instead of coronary angiography (CAG). Methods This was a prospective cohort study of patients referred for valve surgery in the Capital Region of Denmark and Odense University Hospital from the 1 February 2015 to the 1 February 2017. MSCT was implemented for patients with a CT-Valve score ≤7 at the referring physician's discretion. Patients with a history of CAD or chronic kidney disease were excluded. The primary outcome was the proportion of patients needing reevaluation with CAG after MSCT and risk of CAD among the patients determined to be low to intermediate risk. Results In total, 1149 patients were included. The median score was 9 (IQR 3) and 339 (30%) had a score ≤7. MSCT was used for 117 patients. Of these 29 (25%) were reevaluated and 9 (7.7%) had CAD. Of the 222 patients with a score ≤7 that did not receive an MSCT, 14 (6%) had significant CAD. The estimated total cost of evaluation among patients with a score ≤7 before implementation was €132 093 compared with €79 073 after, a 40% reduction. Similarly, estimated total radiation before and after was 608 mSv and 362 mSv, a 41% reduction. Follow-up at a median of 32 months (18-48) showed no ischaemic events for patients receiving only MSCT. Conclusion The CT-Valve score is a valid method for determining risk of CAD among patients with valvular heart disease. Using a score ≤7 as a cut-off for the use of MSCT is safe and cost-effective.